Scientists perform first pig-to-human lung transplant

Scientists have dreamed for centuries about using animal organs to treat ailing humans. In recent years, those efforts have begun to bear fruit: Researchers have begun transplanting the hearts and kidneys of genetically modified pigs into patients, with varying degrees of success.

But lungs are notoriously difficult to transplant, even from human to human, and mortality rates are high. Now, in the first procedure of its kind, Chinese scientists on Monday reported transplanting a lung from a pig into a brain-dead man.

The organ sustained damage after it was transplanted but functioned to some degree, scientists at Guangzhou Medical University reported in the journal Nature Medicine. The organ was removed after nine days.

American scientists called the procedure exciting but urged caution